I remember when he was this 7-4-1 lower-level guy who came in and upset Miguel Torres. He then proceeded to head kick, leg kick, dominate, and submit his way to the title and then through to the present, where he is without question a top-3 BW outside the UFC.
His striking is excellent, his jiu-jitsu is pretty high-level, and his leg kicks are nasty. His defensive wrestling hasn't been tested much, but since he's a regular training partner for Frankie then I'll go out on a limb and say that's it's at least up to par. And he's getting batter every time.
If he does come to the UFC, then he certainly won't be making the same kind of money that WSOF and the sponsors are paying him, but I would give him solid odds to be a top-4 bantamweight.